Studies are proposed to explore the scope of oxygen-17 nuclear magnetic resonance (nmr) in the investigation of structure and conformation of peptides and evaluation of the dynamics of their molecular motions. Enhancement of oxygen-17 signal to noise ratio will be achieved a) by synthetic incorporation of oxygen-17 at specific and selective carbonyl and hydroxyl groups of amino acids and peptides as well as their derivatives; b) by the use of large bore probes; c) by studies at high magnetic fields generated by superconducting magnets (WH-360 and CXP-180). Various structural and conformational features of peptides will be investigated by studies of the chemical shift, nuclear relaxation and variation of pulse repetition rate. In particular the effect of various hydrogen bonded states (non-hydrogen bonded, inter- and intramolecular hydrogen bond) will be explored as a function of temperature, solute concentration, pH and solvent composition. Thermodynamic and kinetic parameters characterizing internal modes of motion of "quasi" rigid molecules, and the formation of rupture of hydrogen bonds will be determined. These investigations should demonstrate the potential use of oxygen-17 in conformational studies and will open new avenues in the theoretical understanding of peptide conformation.